This invention relates to rotary engines and, more specifically, to improved apex seals for rotary engines.
Prior art of possible relevance includes U.S. Pat. Nos. 3,113,526 to Paschke; 3,197,125 to Bachman et al; 3,300,124 to Jones; 3,658,451 to Gomada; 3,672,798 to Scherenberg; and 3,785,745 to Lamm.
Even though the operating and basic construction principles of rotary engines such as the so-called "Wankel" have been known for many years, the same have not been commercialized to any appreciable extent principally due to difficulties in solving seal problems. Consequently, there is a real need for more reliable seals, such as apex seals, in rotary engines.
One particular difficulty encountered with apex seals is their tendency to bow in a concave fashion looking radially outwardly of the rotor when under load. Consequently, leakage spaces form at the edges of the seal.
There have been various proposals to solve this difficulty such as the use of side-by-side sealing elements provided with grooves such as shown by Paschke in his previously identified patent. However, such constructions tend to be prone to sticking, resulting in seal failure and/or inability to flex to close leakage openings around the seals.